Email Address:
jlehrter@disl.org
Phone Number:
(251) 861-2141 Ext:7567
CV
Personal Website

Dr. John Lehrter

Professor

Marine Sciences

Bio

Senior Marine Scientist, Dauphin Island Sea Lab
Ph.D. 2003, University of Alabama

Emphasis: Nutrient biogeochemistry and eutrophication impacts in coastal ecosystems

Research Interests

Multiple Stressor Impacts to Coastal Ecosystems

Estuaries and coastal ecosystems located at the land-sea interface are among the most highly productive systems on Earth and due their proximity to land are also among the most susceptible to human activities. The impacts to these systems therefore are of great societal concern. Work in our lab has focused on land-use change, nutrient pollution, eutrophication, and hypoxia as primary stressors. We have hypothesized that these stressors along with a myriad of other stressors such as, ocean acidification, increasing sea surface temperatures, alterations in watershed hydrology, and harvesting of natural resources have combined to impact habitats and their supported flora and fauna. Our research aims to disentangle and quantify how these stressors manifest both individually and cumulatively in coastal systems, and to predict how the systems may change following management or restoration activities.

Marine Biogeochemistry and Ecosystem Modeling

Our observational studies seek to quantify how marine biogeochemical cycles are affected by changes in biophysical forcing and in turn how the cycles affect lower trophic level metabolism. Often, though, it is not possible to isolate how individual or cumulative forcing affects an ecosystem through observation alone. In such cases, we employ numerical ecosystem models to tease apart the complexity that cannot be observed directly. Ecosystem models are also useful for data synthesis and identification of knowledge gaps in our understanding of specific processes, which can lead to new hypotheses about how marine systems are organized and operate. We have developed and applied models ranging from coastal watershed hydrologic and nutrient exports models to coastal three-dimensional hydrodynamic and biogeochemical models to understand and predict how local and global anthropogenic perturbations impact marine systems.

Ocean Color Remote Sensing

There has been a revolution over the past decade in the use of satellite ocean color data to better understand spatial and temporal dynamics of marine systems. Current satellites provide global, spatially synoptic, coastal data on a daily frequency. Our work revolves around developing new algorithms to retrieve water quality data from satellites in optically complex coastal systems and in the application of these data to develop water quality time-series that can be analyzed to determine the main factors, human vs natural, that drive variability in water quality.

Join the Lab

Our lab offers research and training opportunities for graduate and undergraduate students and postdocs.

PhD and MS graduate students are accepted through the Stokes School of Marine & Environmental Sciences at the University of South Alabama. Admission is competitive and requires a minimum GPA of 3.0 and a GRE score of 300 or better for combined verbal and quantitative subtests. If you meet these criteria, please send your GRE and GPA scores, a current CV, and a brief statement of research interests to jlehrter@disl.org.

We accept undergraduate volunteers who are interested in pursuing science as a career. We expect at least a semester-long commitment, during which time you will work on your own project with guidance and consultation from more senior lab members. This means that during the semester we expect at least 12 hours per week and during summer at least 20 hours per week, preferably full time. Please contact John Lehrter to discuss interests and potential projects.

Publications

For a complete list of my publications, please visit my Google Scholar site at: https://scholar.google.com/citations?user=v09th-sAAAAJ&hl=en

Courses

Marine Resource Management